Lac Operon: The genetic unit consisting of three structural genes, an operator and a regulatory gene. The regulatory gene controls the synthesis of the three structural genes: BETA-GALACTOSIDASE and beta-galactoside permease (involved with the metabolism of lactose), and beta-thiogalactoside acetyltransferase.Operon: In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.Gene Regulatory Networks: Interacting DNA-encoded regulatory subsystems in the GENOME that coordinate input from activator and repressor TRANSCRIPTION FACTORS during development, cell differentiation, or in response to environmental cues. The networks function to ultimately specify expression of particular sets of GENES for specific conditions, times, or locations.Lactose: A disaccharide of GLUCOSE and GALACTOSE in human and cow milk. It is used in pharmacy for tablets, in medicine as a nutrient, and in industry.Lac Repressors: Bacterial repressor proteins that bind to the LAC OPERON and thereby prevent the synthesis of proteins involved in catabolism of LACTOSE. When lactose levels are high lac repressors undergo an allosteric change that causes their release from the DNA and the resumption of lac operon transcription.Galactosidases: A family of galactoside hydrolases that hydrolyze compounds with an O-galactosyl linkage. EC 3.2.1.-.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Isopropyl Thiogalactoside: A non-metabolizable galactose analog that induces expression of the LAC OPERON.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.beta-Galactosidase: A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.Enzyme Repression: The interference in synthesis of an enzyme due to the elevated level of an effector substance, usually a metabolite, whose presence would cause depression of the gene responsible for enzyme synthesis.Bacterial Proteins: Proteins found in any species of bacterium.Genes, Bacterial: The functional hereditary units of BACTERIA.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Nitrophenylgalactosides: Includes ortho-, meta-, and para-nitrophenylgalactosides.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Molecular Biology: A discipline concerned with studying biological phenomena in terms of the chemical and physical interactions of molecules.Stochastic Processes: Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.Systems Biology: Comprehensive, methodical analysis of complex biological systems by monitoring responses to perturbations of biological processes. Large scale, computerized collection and analysis of the data are used to develop and test models of biological systems.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Repressor Proteins: Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Neural Networks (Computer): A computer architecture, implementable in either hardware or software, modeled after biological neural networks. Like the biological system in which the processing capability is a result of the interconnection strengths between arrays of nonlinear processing nodes, computerized neural networks, often called perceptrons or multilayer connectionist models, consist of neuron-like units. A homogeneous group of units makes up a layer. These networks are good at pattern recognition. They are adaptive, performing tasks by example, and thus are better for decision-making than are linear learning machines or cluster analysis. They do not require explicit programming.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Metabolic Networks and Pathways: Complex sets of enzymatic reactions connected to each other via their product and substrate metabolites.Epistasis, Genetic: A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Genes, Regulator: Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for PROTEINS or RNAs which have GENE EXPRESSION REGULATION functions.rRNA Operon: Genetic loci which direct transcription of ribosomal RNA in bacterial operons. They are designated rrnB, rrnC, rrnD, etc. according to the structural position of the transcription unit in the DNA sequence.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Cyclic AMP Receptor Protein: A transcriptional regulator in prokaryotes which, when activated by binding cyclic AMP, acts at several promoters. Cyclic AMP receptor protein was originally identified as a catabolite gene activator protein. It was subsequently shown to regulate several functions unrelated to catabolism, and to be both a negative and a positive regulator of transcription. Cell surface cyclic AMP receptors are not included (CYCLIC AMP RECEPTORS), nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins, which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.Operator Regions, Genetic: The regulatory elements of an OPERON to which activators or repressors bind thereby effecting the transcription of GENES in the operon.Thiogalactosides: Galactosides in which the oxygen atom linking the sugar and aglycone is replaced by a sulfur atom.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Genetics, Microbial: A subdiscipline of genetics which deals with the genetic mechanisms and processes of microorganisms.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Bacteriophage mu: A temperate coliphage, in the genus Mu-like viruses, family MYOVIRIDAE, composed of a linear, double-stranded molecule of DNA, which is able to insert itself randomly at any point on the host chromosome. It frequently causes a mutation by interrupting the continuity of the bacterial OPERON at the site of insertion.Metabolism: The chemical reactions that occur within the cells, tissues, or an organism. These processes include both the biosynthesis (ANABOLISM) and the breakdown (CATABOLISM) of organic materials utilized by the living organism.Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.Galactose: An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Enzyme Induction: An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Transduction, Genetic: The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.Protein Interaction Mapping: Methods for determining interaction between PROTEINS.Coliphages: Viruses whose host is Escherichia coli.Genetic Code: The meaning ascribed to the BASE SEQUENCE with respect to how it is translated into AMINO ACID SEQUENCE. The start, stop, and order of amino acids of a protein is specified by consecutive triplets of nucleotides called codons (CODON).Quantitative Trait Loci: Genetic loci associated with a QUANTITATIVE TRAIT.Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.DNA, Recombinant: Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Nerve Net: A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.Gene Expression Regulation, Fungal: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.SOS Response (Genetics): An error-prone mechanism or set of functions for repairing damaged microbial DNA. SOS functions (a concept reputedly derived from the SOS of the international distress signal) are involved in DNA repair and mutagenesis, in cell division inhibition, in recovery of normal physiological conditions after DNA repair, and possibly in cell death when DNA damage is extensive.Bacteriophage lambda: A temperate inducible phage and type species of the genus lambda-like viruses, in the family SIPHOVIRIDAE. Its natural host is E. coli K12. Its VIRION contains linear double-stranded DNA with single-stranded 12-base 5' sticky ends. The DNA circularizes on infection.Genome, Fungal: The complete gene complement contained in a set of chromosomes in a fungus.DNA-Directed RNA Polymerases: Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Proteome: The protein complement of an organism coded for by its genome.Bayes Theorem: A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.Genetic Engineering: Directed modification of the gene complement of a living organism by such techniques as altering the DNA, substituting genetic material by means of a virus, transplanting whole nuclei, transplanting cell hybrids, etc.Nonlinear Dynamics: The study of systems which respond disproportionately (nonlinearly) to initial conditions or perturbing stimuli. Nonlinear systems may exhibit "chaos" which is classically characterized as sensitive dependence on initial conditions. Chaotic systems, while distinguished from more ordered periodic systems, are not random. When their behavior over time is appropriately displayed (in "phase space"), constraints are evident which are described by "strange attractors". Phase space representations of chaotic systems, or strange attractors, usually reveal fractal (FRACTALS) self-similarity across time scales. Natural, including biological, systems often display nonlinear dynamics and chaos.Homeodomain Proteins: Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).Flowers: The reproductive organs of plants.Bacillus subtilis: A species of gram-positive bacteria that is a common soil and water saprophyte.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Yeasts: A general term for single-celled rounded fungi that reproduce by budding. Brewers' and bakers' yeasts are SACCHAROMYCES CEREVISIAE; therapeutic dried yeast is YEAST, DRIED.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Caenorhabditis elegans: A species of nematode that is widely used in biological, biochemical, and genetic studies.Saccharomyces cerevisiae Proteins: Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.User-Computer Interface: The portion of an interactive computer program that issues messages to and receives commands from a user.Eye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Feedback, Physiological: A mechanism of communication with a physiological system for homeostasis, adaptation, etc. Physiological feedback is mediated through extensive feedback mechanisms that use physiological cues as feedback loop signals to control other systems.Body Patterning: The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.Computer Communication Networks: A system containing any combination of computers, computer terminals, printers, audio or visual display devices, or telephones interconnected by telecommunications equipment or cables: used to transmit or receive information. (Random House Unabridged Dictionary, 2d ed)Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Databases, Genetic: Databases devoted to knowledge about specific genes and gene products.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Genes, Fungal: The functional hereditary units of FUNGI.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Lactose Factors: Plasmids which determine the ability of a bacterium to ferment lactose.Kinetics: The rate dynamics in chemical or physical systems.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Databases, Factual: Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Community Networks: Organizations and individuals cooperating together toward a common goal at the local or grassroots level.Crosses, Genetic: Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.Drosophila Proteins: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.Gene Expression Regulation, Plant: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.Cyclic AMP: An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Mutagenesis, Insertional: Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.trans-Golgi Network: A network of membrane compartments, located at the cytoplasmic side of the GOLGI APPARATUS, where proteins and lipids are sorted for transport to various locations in the cell or cell membrane.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Genes, Plant: The functional hereditary units of PLANTS.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Embryonic Development: Morphological and physiological development of EMBRYOS.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Genetic Variation: Genotypic differences observed among individuals in a population.ArabinoseData Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Protein Interaction Maps: Graphs representing sets of measurable, non-covalent physical contacts with specific PROTEINS in living organisms or in cells.Morphogenesis: The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Regulon: In eukaryotes, a genetic unit consisting of a noncontiguous group of genes under the control of a single regulator gene. In bacteria, regulons are global regulatory systems involved in the interplay of pleiotropic regulatory domains and consist of several OPERONS.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Kluyveromyces: An ascomycetous yeast of the fungal family Saccharomycetaceae, order SACCHAROMYCETALES.Arabidopsis Proteins: Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Cell Cycle: The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.Open Reading Frames: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.MicroRNAs: Small double-stranded, non-protein coding RNAs, 21-25 nucleotides in length generated from single-stranded microRNA gene transcripts by the same RIBONUCLEASE III, Dicer, that produces small interfering RNAs (RNA, SMALL INTERFERING). They become part of the RNA-INDUCED SILENCING COMPLEX and repress the translation (TRANSLATION, GENETIC) of target RNA by binding to homologous 3'UTR region as an imperfect match. The small temporal RNAs (stRNAs), let-7 and lin-4, from C. elegans, are the first 2 miRNAs discovered, and are from a class of miRNAs involved in developmental timing.Eye ProteinsSequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Wireless Technology: Techniques using energy such as radio frequency, infrared light, laser light, visible light, or acoustic energy to transfer information without the use of wires, over both short and long distances.Conjugation, Genetic: A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.Transcriptional Activation: Processes that stimulate the GENETIC TRANSCRIPTION of a gene or set of genes.Sigma Factor: A protein which is a subunit of RNA polymerase. It effects initiation of specific RNA chains from DNA.Laccase: A copper-containing oxidoreductase enzyme that catalyzes the oxidation of 4-benzenediol to 4-benzosemiquinone. It also has activity towards a variety of O-quinols and P-quinols. It primarily found in FUNGI and is involved in LIGNIN degradation, pigment biosynthesis and detoxification of lignin-derived products.Terminator Regions, Genetic: DNA sequences recognized as signals to end GENETIC TRANSCRIPTION.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Neural Pathways: Neural tracts connecting one part of the nervous system with another.F Factor: A plasmid whose presence in the cell, either extrachromosomal or integrated into the BACTERIAL CHROMOSOME, determines the "sex" of the bacterium, host chromosome mobilization, transfer via conjugation (CONJUGATION, GENETIC) of genetic material, and the formation of SEX PILI.Escherichia coli K12: A species of gram-negative, rod-shaped bacteria belonging to the K serogroup of ESCHERICHIA COLI. It lives as a harmless inhabitant of the human LARGE INTESTINE and is widely used in medical and GENETIC RESEARCH.Artificial Gene Fusion: The in vitro fusion of GENES by RECOMBINANT DNA techniques to analyze protein behavior or GENE EXPRESSION REGULATION, or to merge protein functions for specific medical or industrial uses.Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.Tryptophan: An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Pseudomonas putida: A species of gram-negative, aerobic bacteria isolated from soil and water as well as clinical specimens. Occasionally it is an opportunistic pathogen.La Crosse virus: A serotype of the species California encephalitis virus (ENCEPHALITIS VIRUS, CALIFORNIA), in the genus ORTHOBUNYAVIRUS, causing human MENINGOENCEPHALITIS. This is the agent most responsible for California encephalitis (ENCEPHALITIS, CALIFORNIA), the most prevalent mosquito-borne disease recognized in the United States.Phosphoenolpyruvate Sugar Phosphotransferase System: The bacterial sugar phosphotransferase system (PTS) that catalyzes the transfer of the phosphoryl group from phosphoenolpyruvate to its sugar substrates (the PTS sugars) concomitant with the translocation of these sugars across the bacterial membrane. The phosphorylation of a given sugar requires four proteins, two general proteins, Enzyme I and HPr and a pair of sugar-specific proteins designated as the Enzyme II complex. The PTS has also been implicated in the induction of synthesis of some catabolic enzyme systems required for the utilization of sugars that are not substrates of the PTS as well as the regulation of the activity of ADENYLYL CYCLASES. EC 2.7.1.-.Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Mutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Tryptophanase: An enzyme that catalyzes the conversion of L-tryptophan and water to indole, pyruvate, and ammonia. It is a pyridoxal-phosphate protein, requiring K+. It also catalyzes 2,3-elimination and beta-replacement reactions of some indole-substituted tryptophan analogs of L-cysteine, L-serine, and other 3-substituted amino acids. (From Enzyme Nomenclature, 1992) EC 4.1.99.1.Symporters: Membrane transporters that co-transport two or more dissimilar molecules in the same direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.
Gene regulatory network. *cis-regulatory element. *lac operon. *Post-transcriptional *sequestration (P-bodies) ... Although as early as 1951, Barbara McClintock showed interaction between two genetic loci, Activator (Ac) and Dissociator (Ds ... The Lac operon is an interesting example of how gene expression can be regulated. ... the first discovery of a gene regulation system is widely considered to be the identification in 1961 of the lac operon, ...
... and cellular biology portal Evolutionary developmental biology Genetic code Gene regulatory network L-arabinose operon Protein ... This allows for expression of the operon. The lac operon is a negatively controlled inducible operon, where the inducer ... The first operon to be described was the lac operon in E. coli. The 1965 Nobel Prize in Physiology and Medicine was awarded to ... The lac operon of the model bacterium Escherichia coli was the first operon to be discovered and provides a typical example of ...
The Lac operon is an interesting example of how gene expression can be regulated. Viruses, despite having only a few genes, ... Often, one gene regulator controls another, and so on, in a gene regulatory network. Gene regulation is essential for viruses, ... Although as early as 1951, Barbara McClintock showed interaction between two genetic loci, Activator (Ac) and Dissociator (Ds ... thus impeding the expression of the gene.The image to the right demonstrates regulation by a repressor in the lac operon. ...
The lac operon is used in the biotechnology industry for production of recombinant proteins for therapeutic use. The gene or ... Friedland, A.E.; Lu, T.K; Wang, X.; Shi, D.; Church, G.; Collins, J.J. (2009). "Synthetic Gene Networks That Count". Science. ... Gardner, T.s., Cantor, C.R., Collins, J. Construction of a genetic toggle switch in Escherichia coli. Nature 403, 339-342 (20 ... The first natural gene circuit studied in detail was the lac operon. In studies of diauxic growth of E. coli on two-sugar media ...
An example of a cis-acting regulatory sequence is the operator in the lac operon. This DNA sequence is bound by the lac ... CREs are vital components of genetic regulatory networks, which in turn control morphogenesis, the development of anatomy, and ... mRNA Other Regulation of gene expression cis-regulatory module Gene regulatory network Operon Promoter Trans-acting factor Rfam ... The lac operator is, thus, considered to "act in cis" on the regulation of the nearby genes. The operator itself does not code ...
... network Gene testing Gene theft Gene therapy Gene transfer Genetic algorithm Genetic architecture Genetic carrier Genetic code ... Kartagener's syndrome Karyokinesis Karyotype Kilobase Kin selection Kinetochore Klinefelter syndrome Knockout Lac operon ... Europe Genetic illness Genetic informatics Genetic linkage map Genetic load Genetic map Genetic marker Genetic material Genetic ... Genetic counseling Genetic deletion Genetic determinism Genetic disorder Genetic dissection Genetic drift Genetic engineering ...
In 1961, Jacques Monod, Jean-Pierre Changeux and François Jacob discovered the lac operon in the bacterium Escherichia coli. It ... The regulatory networks involved are often very large. Each regulatory protein controls "scores to hundreds" of cis-regulatory ... These genes are called the developmental-genetic toolkit. They are highly conserved among phyla, meaning that they are ancient ... Such a cascading regulatory network has been studied in detail in the development of the fruit fly embryo. The young embryo is ...
Lac operon http://www.sci.sdsu.edu/~smaloy/MicrobialGenetics/topics/in-vitro-genetics/expression-vectors.html ORegAnno - Open ... "Analysis of Biological Networks: Transcriptional Networks - Promoter Sequence Analysis" (PDF). Tel Aviv University. Retrieved ... Some cases of many genetic diseases are associated with variations in promoters or transcription factors. Examples include: ... meaning that besides the lac promoter, the lac operator is also present. If the lac operator were not present the IPTG would ...
Lac operon). The products of operon genes typically have related functions and are involved in the same regulatory network. ... The genetic variation in relative frequencies of different alleles in a population is due to both natural selection and genetic ... The regulation of lactose metabolism genes in E. coli (lac operon) was the first such mechanism to be described in 1961. A ... The related term synthetic biology is sometimes used to refer to extensive genetic engineering of an organism. Genetic ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... Pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is genes that ... Sickle cell anemia is a genetic disease that causes deformed red blood cells with a rigid, crescent shape instead of the normal ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... Quantitative genetics focuses on genetic variance due to genetic interactions. Any two locus interactions at a particular gene ... In this regression, the observed two locus genetic effects are treated as dependent variables and the "pure" genetic effects ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... Protection from major genetic mutation[edit]. In contrast to the view that sex promotes genetic variation, Heng,[11] and ... Genetic heritability cost of sex[edit]. A sexually reproducing organism only passes on ~50% of its own genetic material to each ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... St Johnston D (2002). "The art and design of genetic screens: Drosophila melanogaster". Nat Rev Genet. 3 (3): 176-188. doi: ... Lawson N. D., Wolfe S. A. (2011). "Forward and Reverse Genetic Approaches for the Analysis of Vertebrate Development in the ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... PAX6 is a member of the Pax gene family which is responsible for carrying the genetic information that will encode the Pax-6 ... Freund C, Horsford DJ, McInnes RR (1996). "Transcription factor genes and the developing eye: a genetic perspective". Human ...
In terms of the lac operon, the negative regulator would be the lac repressor which binds to the promoter in the same site that ... "BACTERIOLOGY - CHAPTER NINE GENETIC REGULATORY MECHANISMS". Microbiology and Immunology Online. University of South Carolina ... "Identification of co-expression gene networks, regulatory genes and pathways for obesity based on adipose tissue RNA Sequencing ... lac Z, lac Y, and lac A. Negative regulators are regulatory elements which obstruct the binding of RNA polymerase to the ...
Gene regulatory network. *cis-regulatory element. *lac operon. *Post-transcriptional *sequestration (P-bodies) ... Lamb MJ, Jablonka E (2005). Evolution in four dimensions: genetic, epigenetic, behavioral, and symbolic variation in the ... Malanga M, Althaus FR (2005). "The role of poly(ADP-ribose) in the DNA damage signaling network". Biochem Cell Biol. 83 (3): ... These newly constructed networks function very efficiently via new pathways as soon as drugs of abuse are further taken ... In ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... Role in genetic disorders[edit]. Many genetic disorders involve hereditary defects in receptor genes. Often, it is hard to ...
... genetic code - genetic equilibrium - genetic fingerprint - genetic recombination - genetics - gene regulatory network - genetic ... kwashiorkor Lac repressor - lactic acid autotroph - lagging strand - lambda phage - larva - leading strand - leaf - White blood ... operon - organ - organelle - organism - origin of life - Oscar Hertwig - osmosis - osmoregulation - Oswald Avery - outbreak - ...
Lac operon *^ "Expression vectors". www.sci.sdsu.edu.. External links[edit]. Wikimedia Commons has media related to Genetic ... "Analysis of Biological Networks: Transcriptional Networks - Promoter Sequence Analysis" (PDF). Tel Aviv University. Retrieved ... meaning that besides the lac promoter, the lac operator is also present. If the lac operator were not present the IPTG would ... For instance, in E. coli, ~60% of random sequences can evolve expression levels comparable to the wild-type lac promoter with ...
Evolution of genetic systems. *Evolvability. *Robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ... The degree of interpenetration of two neutral networks of different activities in sequence space will determine how easy it is ...
Evolution of genetic systems. *Evolvability. *Mutational robustness. *Neutral networks. *Evolution of sexual reproduction ... Lac operon. *Eric F. Wieschaus. *Christiane Nüsslein-Volhard. *William McGinnis. *Mike Levine ...
... suspected from the experiments on the biology of the bacteriophage lambda and the regulation of the Escherichia coli lac operon ... O'Neill M.C (1991). "Training back-propagation neural networks to define and detect DNA-binding sites". Nucleic Acids Research ... Jacob F, Monod J (1961). "Genetic regulatory mechanisms in the synthesis of proteins". Journal of Molecular Biology. 3 (3): 318 ... Gilbert W, Maxam A (1973). "The nucleotide sequence of the lac operator". Proceedings of the National Academy of Sciences of ...
François Jacob and Jacques Monod followed the 1959 PaJaMo experiment with a series of publications regarding the lac operon ... Oswald Avery showed in 1943 that DNA was likely the genetic material of the chromosome, not its protein; the issue was settled ... networks, robots, satellites, and compute power for data collection, storage, analysis, modeling, visualization, and ... Following the establishment of the Central Dogma and the cracking of the genetic code, biology was largely split between ...
Gene regulatory network. *cis-regulatory element. *lac operon. *Post-transcriptional *sequestration (P-bodies) ... A molecule that allows the genetic material to be realized as a protein was first hypothesized by François Jacob and Jacques ... which was useful for cracking the genetic code. RNA synthesis by RNA polymerase was established in vitro by several ... "MicroRNAs in the DNA Damage/Repair Network and Cancer". International Journal of Genomics. 2014: 820248. doi:10.1155/2014/ ...
Gene regulatory network. *cis-regulatory element. *lac operon. *Post-transcriptional *sequestration (P-bodies) ... Degeneracy of the genetic code was identified by Lagerkvist.[2] For instance, codons GAA and GAG both specify glutamic acid and ... Inverse table for the standard genetic code (compressed using IUPAC notation) Amino acid. Codons. Compressed Amino acid. Codons ... Shu, Jian-Jun (2017). "A new integrated symmetrical table for genetic codes". BioSystems. 151: 21-26. arXiv:1703.03787. doi: ...
... ... "Stochasticity and cell population heterogeneity in an artificial lac operon genetic network." (2009) Diss., Rice University. ... to demonstrate the effect of stochasticity on cell population heterogeneity in an artificial lac operon genetic network. During ... stochasticity generates complex behavior and phenotypic heterogeneity in the case of an artificial lac operon genetic network, ...
Genetic and metabolic analyses of Escherichia coli strains showed that over-expression of PanB leads to accumulation of the ... Genetic and metabolic analyses of Escherichia coli strains showed that over-expression of PanB leads to accumulation of the ... Comparison of deterministic and stochastic models of the lac operon genetic network. Biophys. J. 96, 887-906. doi: 10.1016/j. ... Genetic and Metabolic Evidence Favor a Role of PanB in THF Damage. If a side-reaction of PanB cleaves CH2-THF (Figure 3), then ...
... coli lac operon, the lambda phage bistable switch, the "Repressilator" synthetic genetic network. Eukaryotic genome ... Robustness of genetic networks. Self-regulation in biochemical networks: metabolic control theory, flux balance analysis. ... biologically inspired artificial neural networks, neural network training, convolutional neural networks, feedforward- ... Bayesian approaches, naïve Bayes classifiers, Bayesian networks, probabilistic classifiers, network structure learning, ...
COLI LAC OPERON Figure 1. Electron micrograph of growing E. coli. Some show the constriction at the location where daughter ... COLI LAC OPERON CHAPTER 13 CHAPTER 13 PROKARYOTE GENES: E. ... and Stochastic Models of the lac Operon Genetic Network ... COLI LAC OPERON 4. THE USE OF MUTANTS TO STUDY THE LAC OPERON 4.1. SINGLE MUTANTS OF THE LAC OPERON The lac operon and its ... Modeling network dynamics: the lac operon, a case study Modeling network dynamics: the lac operon, a case study José M. G. ...
Genetic and biochemical networks, chemical kinetics, deterministic and stochastic descriptions. Other network types: Regulatory ... Quantitative models for E Coli: lac operon and lambda switch. The chemotactic module in E. Coli. Pathways and pathway inference ... Computer Networking: Introduction to networking: Associated hardware devices, gadgets (Router, Switch etc.), Network Topologies ... Topology of genetic and metabolic networks. Software for systems biology. SBML, and open source programs eCell, Virtual Cell, ...
Deterministic and stochastic population-level simulations of an artificial lac operon genetic network. ... In addition, mt genome sequences have provided useful markers for investigating population genetic structures, systematics and ...
Therefore, simulations may assist in designing novel gene network architectures consisting of tetracycline operon components. ... We find that lack of one of the promoters of the tetracycline operon has no influence on the total behavior of this system ... In this paper, we investigate the dynamics of the tetracycline operon. To this end, we develop a mathematical model guided by ... Because of the performance of the molecular elements of the tetracycline operon, these elements are widely used as parts of ...
Repressor (see Lac repressor) and activator proteins are used to create genetic operons, which were identified by Francois ... When more people are encouraged to join a network this increases the reach of the network therefore the network expands ever ... Genetic engineers have constructed and tested simple positive feedback networks in bacteria to demonstrate the concept of ... A classic example of positive feedback is the lac operon in Escherichia coli. Positive feedback plays an integral role in ...
The lac operon is an example of a relatively simple genetic network and is one of the best-studied structures in the ... Angelova, Maia and Ben Halim, Asma (2011) Dynamic model of gene regulation for the lac operon. Journal of Physics: Conference ... In this work we consider a deterministic model of the lac operon with a noise term, representing the stochastic nature of the ... Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. ...
Kinetic mass action models (eg LAC operon) * Trajectory Analysis * Model Reconstruction & Validation 11. Evolution * Models of ... Heuristic methods, neural networks, simulated annealing, genetic algorithms * Statistical distributions, models, estimation * ...
"Comparison of Deterministic and Stochastic Models of the ,i>lac,/i> Operon Genetic Network." Biophysical journal 96.3 (2009): ...
... the lac operon -- Using a good natural system -- Improving a good system -- Designing genetic networks -- Switching from one ... the lac operon -- Using a good natural system -- Improving a good system -- Designing genetic networks -- Switching from one ... Organizing genetic material -- DNA : the recipe for life -- Perfect plasmids -- DNA replication -- Assembling the cellular ... Organizing genetic material -- DNA : the recipe for life -- Perfect plasmids -- DNA replication -- Assembling the cellular ...
Genetic Switch,Genetic Toggle Switch]] #[[Transcription Networks]] #[[Network Motifs]] #[[Autoregulation]] #[[Negative ... lac operon]] #[[Gene Regulation and Protein Levels]] #[[Simple Gene Regulation]] #[[Statistical Mechanics of Binding]] #[[ ... Molecular Biology]] #[[Saccharides]] #[[DNA Structure]] #[[Central Dogma]] #[[Promoter Strength]] #[[Chromatin]] #[[Genetic ... Genetic Switch]] #[[Differenzengleichungen]] #[[Poincare Abbildungen]] #[[Floquet - Stabilität von Abbildungen]] #[[Logistische ...
Gene networks: basic concepts, computational model such as Lambda receptor and lac operon ... Use of Genetic Algorithms, Neural Networks and Principle Components Analysis in the QSAR equations ... Use of various derived databases in function assignment, use of SNPs for identification of genetic traits ...
... and cellular biology portal Evolutionary developmental biology Genetic code Gene regulatory network L-arabinose operon Protein ... This allows for expression of the operon. The lac operon is a negatively controlled inducible operon, where the inducer ... The first operon to be described was the lac operon in E. coli. The 1965 Nobel Prize in Physiology and Medicine was awarded to ... The lac operon of the model bacterium Escherichia coli was the first operon to be discovered and provides a typical example of ...
The Lac operon is an interesting example of how gene expression can be regulated. Viruses, despite having only a few genes, ... Often, one gene regulator controls another, and so on, in a gene regulatory network. Gene regulation is essential for viruses, ... Although as early as 1951, Barbara McClintock showed interaction between two genetic loci, Activator (Ac) and Dissociator (Ds ... thus impeding the expression of the gene.The image to the right demonstrates regulation by a repressor in the lac operon. ...
While there have been numerous studies correlating the architecture of cellular reaction networks with noise tolerance, only a ... The specific binding between regulatory proteins provides a buffer that may prevent the propagation of fluctuations in genetic ... Müller-Hill B: The Lac Operon: A Short History of a Genetic Paradigm. 1996, Walter de GruyterView ArticleGoogle Scholar. ... Gilman A, Arkin A: Genetic Code: Representations and Dynamical Models of Genetic Components and Networks. Annual Reviews in ...
Gene regulatory network. *cis-regulatory element. *lac operon. *Post-transcriptional *sequestration (P-bodies) ... Although as early as 1951, Barbara McClintock showed interaction between two genetic loci, Activator (Ac) and Dissociator (Ds ... The Lac operon is an interesting example of how gene expression can be regulated. ... the first discovery of a gene regulation system is widely considered to be the identification in 1961 of the lac operon, ...
Repressor (see Lac repressor) and activator proteins are used to create genetic operons, which were identified by Francois ... In contrast, artificial systems such as machine learning algorithms or neural networks are adaptive only at two levels or ... It then reproduces this genetic quality during evolution. This cyber-genetic mechanism secures the morphological adjustment in ... Positive Intrinsic Eugenics is: the tendency for genetic improvement within a species, by means of natural procreation, caused ...
Cell Fates as High-dimensional Attractors of Gene Regulatory Networks Sui ... Gene Regulation -- The Lac Operon Gene Regulation -- The Lac Operon Specific proteins are present in different tissues and some ... Nature of Genetic Material. Nature of Genetic Material Core Category Nature of Genetic Material Nature of Genetic Material Core ... Network Analysis. BCH 5101: Analysis of -Omics Data 1/34 Network Analysis BCH 5101: Analysis of -Omics Data 1/34 Network ...
Modelling gene expression control using P systems: the lac operon, a case study. Biosystems 91:438-457. doi:10.1016/j. ... Genetic evidence that the XylS regulator of the Pseudomonas TOL meta operon controls the Pm promoter through weak DNA-protein ... This concept is reminiscent of the parameters used for describing the dynamic behavior of regulatory transcriptional networks ( ... Overexpression of glpF and glpK as a synthetic operon and construction of a glpR complementation plasmid.A synthetic operon, ...
Examples of tightly linked genes having epistatic effects are the major histocompatibility complex and the lac operon in ... acting either additively or as members of some genetic network. Several techniques for inferring are described in Takezawa ( ... Basing selection of parents on predictions of additive genetic values, notable genetic progress has been attained in many ... Wong, G. K., B. Liu, J. Wang, Y. Zhang, X. Yang et al., 2004 A genetic variation map for chicken with 2.8 million single- ...
Vilar J, Guet CC, Leibler S. Modeling network dynamics: the lac operon, a case study. Journal of Cell Biology. 2003;161(3):471- ... Guet CC, Elowitz M, Hsing W, Leibler S. Combinatorial synthesis of genetic networks. Science. 2002;296(5572):1466-1470. doi: ... Vilar J, Guet CC, Leibler S. Modeling network dynamics: the lac operon, a case study. Journal of Cell Biology. 2003;161(3):471- ... Guet CC, Elowitz M, Hsing W, Leibler S. Combinatorial synthesis of genetic networks. Science. 2002;296(5572):1466-1470. doi: ...
... to the right depicts the relationships between the parameters of the lac operon switch described by Ceroni using a network ... IPTG-Inducible Lac Promoter. Part BBa_K418003 This BioBrick contains the genetic coding region for the LacI repressor protein ... Image:LacOperon.jpg,thumb,1040px,,center,Basic Components of a Lac Operon ,cite,. lac. -. op. -wiki,/cite,]] ... Image:LacOperon.jpg,thumb,1040px,,center,Basic Components of a Lac Operon ,cite,. e. -. coli. -wiki,/cite,]] ...
Transcription networks basic concepts - Activators and repressors - Input functions; Logic input functions; Multidimensional ... Modeling network dynamics: the lac operon, a case study Modeling network dynamics: the lac operon, a case study José M. G. ... of Genetic Regulatory Networks Noisy Attractors and Ergodic Sets in Models of Genetic Regulatory Networks Andre S. Ribeiro ... COLI LAC OPERON PROKARYOTE GENES: E. COLI LAC OPERON CHAPTER 13 CHAPTER 13 PROKARYOTE GENES: E. COLI LAC OPERON Figure 1. ...
  • We have analyzed the expression of the vanA operon in the three clinical isolates. (asm.org)
  • Low-level glycopeptide resistance of S. aureus PA-VRSA is thus likely due to instability of the genetic element, plasmid or transposon, carrying the vanA operon associated with a longer lag phase before growth resumes after induction by vancomycin. (asm.org)
  • Vancomycin resistance of Staphylococcus aureus NY-VRSA and VRSA-5 is due to acquisition of a vanA operon located in a Tn 1546 -like element. (asm.org)
  • We have shown that low-level resistance of the PA-VRSA strain is due to loss, at high frequency, of the vanA operon and to a longer lag phase before induction of resistance ( 22 ). (asm.org)
  • In the lac operon, there is a single mrna transcript that includes coding sequences for all three enzymes and is called a polycistronic mrna. (sciencedocbox.com)
  • However, the definition of an operon does not require the mRNA to be polycistronic, though in practice, it usually is. (wikipedia.org)
  • HilC and HilD are encoded in the SPI1 locus, while RtsA is encoded elsewhere in the chromosome in an operon with RtsB, which negatively regulates expression of flhDC and therefore the entire flagellar regulon ( 19 ). (asm.org)
  • In general, biosensors detect changes in (intracellular) concentrations of small compounds and translate this input into a genetic output. (nature.com)
  • This was a true revelation for him and probably influenced him on developing a genetic conception of biochemistry and metabolism. (rug.nl)
  • Previous clinical studies exploring the genetic basis of hypoglycemia revealed two significant mutations in the coding region of the FBPase gene in patients with hypoglycemia, linking the AMP-binding site to the active site of the enzyme. (portlandpress.com)
  • Hence we derive empirically grounded fitness landscapes, which enter a population genetics model including mutations, genetic drift, and selection. (biomedcentral.com)
  • The reconstruction of gene regulatory networks from time series gene expression data is one of the most difficult problems in systems biology. (biomedcentral.com)
  • The third chapter investigates the use of network representations of gene expression in developmental evolution research and takes up some of the conceptual and methodological problems it has generated. (asu.edu)
  • We illustrate how the matrix representation of a TRS coupled with its environment (R*) allows for a sampling of all possible expression states of a given network, and furthermore, how the fundamental subspaces of the matrix provide a way to study key TRS features and may assist in experimental design. (ucsd.edu)
  • Having in mind that small biological systems are subjects to stochasticity, we use a stochastic algorithm to simulate the tetracycline operon behavior. (biomedcentral.com)
  • Recent experiments on isogenic populations of microbes with single-cell resolution [ 1 - 3 ] have demonstrated that stochastic fluctuations, or noise, can override genetic and environmental determinism. (biomedcentral.com)
  • Using stochastic sampling from the Bayes' posterior distribution, our approach can infer different likely network topologies and model parameters along with their respective probabilities from given data. (biomedcentral.com)
  • and the genetic capacity of the smallest known genome, that of Mycoplasma genitalium (Moore, Lawrence). (nap.edu)
  • In this paper, we investigate the dynamics of the tetracycline operon. (biomedcentral.com)
  • Boolean canalization, a type of hierarchical clustering of the inputs of a Boolean function, has been extensively studied in the context of network modeling where each layer of canalization adds a degree of stability in the dynamics of the network. (springeropen.com)
  • Studies published in In Silico Biology generally use theoretical models and computational analysis to gain quantitative insights into regulatory processes and networks, cell physiology and morphology, tissue dynamics and organ systems. (iospress.com)
  • A. Kriete, E. Eils, Revised 3/2/05 Multistability and Multicellularity: Cell Fates as High-dimensional Attractors of Gene Regulatory Networks Sui Huang Vascular Biology Program Children's Hospital / Harvard Medical School Boston, MA I. INTRODUCTION A hall-mark of multicellular organisms is the differentiation of cells into functionally distinct cell types, such as a resting nerve cell or a proliferating skin cell. (docplayer.net)
  • The general problem of optimizing information flow in regulatory networks is difficult. (pnas.org)
  • We provide a brief and accessible introduction to relevant mathematical and computational approaches to model regulatory networks and discuss examples of small network models that have helped generate new insights into plant biology (where small is beautiful), such as in circadian rhythms, hormone signaling, and tissue patterning. (plantcell.org)
  • The generation of these binding sites and of cooperativity between them are essential building blocks in the evolution of complex regulatory networks. (biomedcentral.com)
  • These transcriptional regulatory networks (TRNs) have been mathematically described using a Boolean formalism, in which the state of a gene is represented as either transcribed or not transcribed in response to regulatory signals. (ucsd.edu)
  • Most of these pathways are formed by an intricate and complex network of chain reactions, and can be represented in a human readable form using graphs which describe the cell signaling pathways. (springer.com)
  • Therefore, engineering microbes for improved catabolism of lignin-derived aromatic compounds will require the assembly of an entire network of catabolic reactions, including pathways from genetically intractable strains. (asm.org)
  • The analysis of intrinsic noise reveals biological roles of gene network structures and can lead to a deeper understanding of their evolutionary origin. (pnas.org)
  • Gene network models are needed to interpret the resulting large and complex data sets. (biomedcentral.com)
  • We introduce an approach to gene network modeling based on a scalable linear variant of fuzzy logic: a framework with greater resolution than Boolean logic models, but which, while still semi-quantitative, does not require the precise parameter measurement needed for chemical kinetics-based modeling. (biomedcentral.com)
  • The aims of this review are to illustrate the importance of studying these networks in plants, to provide biologists an overview of mathematical approaches used for modeling them, and to illustrate how systems analysis of small networks can be used to generate biological knowledge, focusing more specifically on recent studies of gene regulatory and signaling networks involved in plant growth and development. (plantcell.org)
  • Linear fuzzy gene networks and exhaustive rule search are the first steps towards a framework for an integrated modeling and experiment approach to high-throughput "reverse engineering" of complex biological systems. (biomedcentral.com)
  • Boolean networks (e.g. [ 8 ]) are computationally simple and do not depend on precise experimental data, and thus they are suitable for handling both the complexity of biological networks and the challenge of generating and comparing multiple hypothetical networks as described in the above scheme. (biomedcentral.com)
  • These properties arise from the integrative functioning of biological networks. (papercept.net)
  • Analysing models of biological networks typically relies on workflows in which different software tools with sensitive parameters are chained together, many times with additional manual steps. (frontiersin.org)
  • The CoLoMoTo Interactive Notebook provides a unified environment to edit, execute, share, and reproduce analyses of qualitative models of biological networks. (frontiersin.org)
  • In other words, a mechanistic understanding of biological networks that are used to generate these datasets is lacking behind. (mdpi.com)
  • This paper is concerned with stability analysis of biological networks modeled as discrete and finite dynamical systems. (springer.com)
  • Genetic Analysis is integrated throughout each chapter, following discussions of important content, to help students immediately apply concepts in a problem-solving context. (b-ok.org)
  • Genetic Analysis: An Integrated Approach , 2/e is extensively updated with relevant, cutting-edge coverage of modern genetics and is supported by MasteringGenetics, the most widely-used homework and assessment program in genetics. (b-ok.org)
  • Concepts of Genetics, Eleventh Edition emphasizes the fundamental ideas of genetics, while exploring modern techniques and applications of genetic analysis. (b-ok.xyz)
  • GENETICS _ is the study of the effect of genetic differences on organisms. (theinfolist.com)
  • The purpose of this work is two-fold: (1) to develop a novel mathematical and computational framework that incorporates the major sources of cell population heterogeneity and (2) to use this framework to demonstrate the effect of stochasticity on cell population heterogeneity in an artificial lac operon genetic network. (rice.edu)
  • Gene regulatory network is a collection of DNA which interact with each other and with other matter in the cell. (northumbria.ac.uk)
  • The second operon includes a lysis gene meant to cause the host cell to burst. (wikipedia.org)
  • b) Describe the structure of microfilaments and microfilament networks and explain how they are assembled and disassembled within a cell. (brainmass.com)
  • c) Outline two functions that microfilament networks play in cell motility. (brainmass.com)
  • This vision holds at all scales and in particular at the genomic scale, with gene regulatory and signaling networks processing multiple cell-autonomous and non-cell-autonomous inputs to generate emergent cellular behaviors. (plantcell.org)
  • 2018. Branched actin networks in dendritic cell biology, IST Austria, 99p. (ist.ac.at)
  • Recently, dynamic network control approaches have been used for the design of new therapeutic interventions and for other applications such as stem cell reprogramming. (springeropen.com)
  • To date, the CoLoMoTo Interactive Notebook provides access to the software tools GINsim, BioLQM, Pint, MaBoSS, and Cell Collective, for the modeling and analysis of Boolean and multi-valued networks. (frontiersin.org)
  • We are working to improve the clinical condition of patients suffering from genetic disorders like Duchenne muscular dystrophy and limb girdle muscular dystrophy types 2A, 2B, and 2D. (stanford.edu)
  • These fluctuations are intrinsic: they are determined by the structure, reaction rates, and species concentrations of the underlying biochemical networks. (pnas.org)
  • One approach to studying the resulting network noise might involve running detailed numerical simulations incorporating all known reactions, rates, and species. (pnas.org)